The invention is related to a structure for providing a damp-proof construction and method for removing factors that generate moisture or dampness in a basement room or subway (collectively referred to as basement herein), thereby keeping the space comfortable and free from moisture.
A basement is generally an underground construction located in the earth as part of the foundation of a building or another substructure. Basements have problems that differ from those of buildings or facilities above the ground. First, water leakage frequently occurs in basements. As water flows underground, this underground water may penetrate the basement through the basement walls or base in contact with the ground.
Second, dew is likely to condense on walls of a basement. Because the interior of the basement is kept at a constant temperature, the basement is relatively warmer in winter and cooler in summer compared to the ground surrounding the basement. Thus, the space within the basement has a temperature that is higher than that of the walls or floor of the basement, thereby causing dew to form on the inner surfaces of the basement. This is called the dew condensation phenomenon.
Third, the humidity is relatively higher inside a basement. The air within a basement becomes very humid due to the water leakage and the dew condensation described above. The humidity in the air provides an environment that allows mold to grow easily. The humidity deteriorates articles or products stored in the basement, and makes it uncomfortable for people residing there.
Considering these points, when a basement is constructed conventionally, damp-proof construction is performed in various manners in order to prevent water leakage, but humidity in the basement air cannot be removed due to the dew condensation phenomenon. That is due to insufficient consideration of the dew condensation phenomenon in the basement. For such humidity to remain within the basement is inappropriate if a person resides there, or if articles or products are stored there. Thus, a basement is not usually utilized to its best capability.
In order to resolve these problems, the inventor of the present invention previously developed a damp-proof construction method for buildings, and obtained U.S. Pat. No. 5,184,437, which issued on Feb. 9, 1993. The ""437 patent discloses a damp-proof construction for building basements and subway construction using a damp-proof brick and plastic palette as damp-proofing elements, in which damp-proof bricks formed of plastic materials are disposed on an underground base surface adjacent the inside surface of the outer wall of a building, and an inner wall is fabricated on the damp-proof brick layer with cement bricks, all on base surface of the underground basement. Plastic palettes are mounted to form a palette layer, a non-woven fabric covers the upper surface of the palette layer to form a non-woven fabric layer, and an upper mortar or reinforced-concrete slab is formed on the non-woven fabric layer. The ""437 patent prevents the inflow of penetrating water from the underground base surface into the building construction, especially through the inner walls and the upper slab of the basement, such that the inner space of the basement remains in a comfortably humid state.
However, the ""437 patent has a problem in that in order to provide sufficient stiffeners to the upper reinforced-concrete slab, careful construction is required. Otherwise, the upper reinforced-concrete slab will not have sufficient hardness. This is because the upper reinforced-concrete slab is mounted directly on the plastic palette layer through the non-woven layer, which may have water permeability. If the non-woven layer is formed of a water-permeable non-woven material and is layered, it acts as a vent layer having water permeability. As a result, the vent layer allows water required for the hydration action of the concrete to leak into the plastic palette layer, before the upper reinforced-concrete slab completely hardens under the hydration action. Thus, when the upper reinforced-concrete slab layer is applied, sufficient water should be supplied during the concrete hardening step to assure the stiffness of the reinforced-concrete slab is sufficient.
Also, the ""437 patent lacks any countermeasure against the dew condensation phenomenon given that the upper reinforced-concrete slab and the inner wall are in contact with the outer walls through the non-woven fabric layer, the plastic palette, and the damp-proof bricks. Dew condenses on the surface of the upper reinforced-concrete slab due to the significant temperature difference between the inner walls and the upper slab, and the interior space of the basement.
The object of the invention is to provide a damp-proof basement construction for preventing water leakage from the ground surrounding the basement into the basement, for removing dew condensation, and for keeping constant room humidity within the basement.
The other object of the invention is to provide a damp-proof basement construction for improving the quality of an upper reinforced-concrete slab, and for establishing a better damp-proof effect in the basement.
According to the invention, a method of construction of a damp-proof basement includes disposing a water-permeable palette layer on a bottom surface of the interior of the basement and spaced from an outer wall of the basement, disposing a water-impermeable vent layer over the water-permeable palette layer, disposing a reinforced-concrete slab on the water-impermeable vent layer and spaced from the outer wall of the basement, and disposing an inner wall of the basement at a periphery of the reinforced-concrete slab and spaced from the outer wall of the basement.
A damp-proof basement construction includes a water-permeable palette layer, disposed on a bottom surface of the interior of a basement and spaced from an outer wall of the basement. A water-impermeable vent layer is disposed over the water-permeable palette layer. A reinforced-concrete slab is disposed on the water-impermeable vent layer and spaced from the outer wall of the basement. An inner wall of the basement is disposed at a periphery of the reinforced-concrete slab and spaced from the outer wall of the basement.
Such a damp-proof construction forms a buffering wall space between the inner and outer walls, separating them from each other. Therefore, even if the waterproofing work on the outer wall or the inner wall is not well done, and the underground water penetrates into the bottom slab of the outer wall, the penetrating water is effectively prevented from flowing into the inner space of the basement through the inner wall and the reinforced-concrete slab due to separation from the outer wall or the bottom slab by the buffering wall space and the water-permeable palette layer.
Also, the air in the basement room does not directly contact the outer wall or the bottom slab, but rather contacts the inner wall or the upper reinforced-concrete slab, thereby effectively preventing the dew condensation phenomenon from occurring thereon. Therefore, it is noted that the invention is different than the ""437 patent in the respect that it prevents water penetration and the dew condensation phenomenon within the inner space of the basement.